Single-walled Carbon Nanotubes Research Articles

Single-Walled Carbon Nanotubes as Optical Transducers for Nanobiosensors In Vivo.

Semiconducting single-walled carbon nanotubes (SWCNTs) may serve as signal transducers for nanobiosensors. Recent studies have developed innovative methods of engineering molecularly specific sensors, while others have devised methods of deploying such sensors within live animals and plants. These advances may potentiate the use of implantable, noninvasive biosensors for continuous drug, disease, and contaminant monitoring based on the optical properties of single-walled carbon nanotubes (SWCNTs). Such tools have substantial potential to improve disease diagnostics, prognosis, drug safety, therapeutic response, and patient compliance. Outside of clinical applications, such sensors also have substantial potential in environmental monitoring or as research tools in the lab. However, substantial work remains to be done to realize these goals through further advances in materials science and engineering. Here, we review the current landscape of quantitative SWCNT-based optical biosensors that have been deployed in living plants and animals. Specifically, we focused this review on methods that have been developed to deploy SWCNT-based sensors in vivo as well as analytes that have been detected by SWCNTs in vivo. Finally, we evaluated potential future directions to take advantage of the promise outlined here toward field-deployable or implantable use in patients.

Stretchable thermoplastic polyurethane/single-walled carbon nanotube masterbatch nanocomposites with enhanced electrical conductivity and thermal properties

A thermoplastic polyurethane (TPU)/single-walled carbon nanotube (SWCNT) nanocomposite was developed using a twin-screw extrusion process followed by injection molding. This study aimed to enhance the properties of TPU by incorporating a SWCNT masterbatch, with a polyol ester serving as the carrier resin. The electrical conductivity, rheological behavior, mechanical performance, and thermal properties of the TPU/SWCNT nanocomposites were systematically evaluated. The incorporation of the SWCNT masterbatch significantly improved the electrical conductivity of the TPU nanocomposites. With SWCNT loading levels below 0.6 wt%, the viscosity and processability of the nanocomposites were maintained. However, a noticeable decrease in viscosity was observed when the SWCNT content exceeded 0.6 wt%. The tensile and storage modulus of the nanocomposites increased, attributed to the stiffness and reinforcing effects of SWCNTs. Despite a slight reduction in tensile strength and elongation at break upon SWCNT addition, the tensile properties of the TPU/SWCNT nanocomposites at a loading of 0.4 wt% remained well-suited for strain sensor applications. The polyol ester in the SWCNT masterbatch facilitated the uniform dispersion of carbon nanotubes within the TPU matrix and enhanced the nucleation ability of SWCNTs, contributing to improved performance characteristics.

Advanced Carbon Nanostructures: Synthesis, Properties, and Applications II

Single-walled carbon nanotubes [...]

Restructuring of Sodium-Lead Alloys during Charge-Discharge Cycling in Sodium-Ion Batteries

Abstract Sodium-ion batteries (NIBs) are of growing interest due to their expected lower cost than many lithium-ion batteries (LIBs). However, most NIBs suffer from lower volumetric energy density than LIBs. Lead (Pb) can replace hard carbon in the NIB negative electrode to substantially increase its volumetric energy density and has been shown to have no capacity fade over hundreds of cycles in half cells. Pb also experiences 387% volume expansion upon full sodiation, which presumably leads to significant changes in the electrode morphology. In this work, the morphology of Pb and Pb-hard carbon blended electrodes is tracked using scanning electron microscopy. As well, each Na-Pb phase is examined to analyze their physical properties. These analyses show that the Pb particles restructure into ~1 µm particles, even after just a single cycle, and surprisingly do not pulverize the hard carbon in a blended electrode. Single-walled carbon nanotubes appear to be necessary to maintain active material electrical connection.

Irreversible effects for SWCNT‐MWCNT/water based flow with Coriolis force over rotating frame: A numerical study

AbstractIn this study, two different types of nanofluids are used: One is the simple nanofluid consist of single‐wall carbon nanotubes (SWCNT), and the other is the hybrid nanofluid composed of single and multi‐wall carbon nanotubes (SWCNT‐MWCNT). The famous Xue model is incorporated for the thermal energy analysis. An important property related to the nanoparticles is the Brownian motion and thermal‐migration, which is described by using Buongiorno's model. The appropriate similarity transformations are used to convert the governing nonlinear partial differential equations into the nonlinear coupled ordinary differential equations for the both velocity and temperature profiles. The numerical solution is obtained for the present problem by using bvp4c Matlab routine. This code is based on the finite difference method that implements the three‐stage Lobatto IIIa formula. The comparative analysis for the entropy generation in rotating frame due to heat transfer, viscous heating, and mass diffusion is the main focus in this study. The impact of different parameters such as, rotational motion , thermomigration and Brownian motion , volume fractions of SWCNT & SWCNT‐MWCNT ,, Eckert number , Lewis number , chemical reaction parameter , Brinkman number the temperature ratio parameter and concentration difference parameter on axial and transverse velocity, temperature profile, entropy generation, and Bejan number are obtained. The obtained results for these different variables are presented through graphs and tabular form. When the solid volume fraction is enhanced, the flow and heat distribution are observed to increase. The Nusselt and Sherwood numbers for both nanofluids are investigated. The decay in Nusselt number is observed as the values of the heat source/sink parameter, thermophoresis, Brownian motion, and Eckert number are increased. However, in the case of Sherwood enhancement an increment in the value of the chemical reaction parameter, thermophoresis, Brownian motion, and Lewis number is observed. The entropy generation is enhanced as a result of increment in Brinkman number and temperature ratio. However, in the case of Bejan number, opposite trend was seen in the entropy generation. For the hybrid nanofluid, the enhancement in both heat transmission and irreversibility effect is observed as compared to simple nanofluid.

Biocompatible Carbon Dots/Polyurethane Composites as Potential Agents for Combating Bacterial Biofilms: N-Doped Carbon Quantum Dots/Polyurethane and Gamma Ray-Modified Graphene Quantum Dots/Polyurethane Composites

Background: Pathogen bacteria appear and survive on various surfaces made of steel or glass. The existence of these bacteria in different forms causes significant problems in healthcare facilities and society. Therefore, the surface engineering of highly potent antimicrobial coatings is highly important in the 21st century, a period that began with a series of epidemics. Methods: In this study, we prepared two types of photodynamic polyurethane-based composite films encapsulated by N-doped carbon quantum dots and graphene quantum dots irradiated by gamma rays at a dose of 50 kGy, respectively. Further, we investigated their structural, optical, antibacterial, antibiofouling and biocompatibility properties. Results: Nanoelectrical and nanomechanical microscopy measurements revealed deviations in the structure of these quantum dots and polyurethane films. The Young’s modulus of elasticity of the carbon and graphene quantum dots was several times lower than that for single-walled carbon nanotubes (SWCNTs) with chirality (6,5). The electrical properties of the carbon and graphene quantum dots were quite similar to those of the SWCNTs (6,5). The polyurethane films with carbon quantum dots were much more elastic and smoother than the films with graphene quantum dots. Antibacterial tests indicated excellent antibacterial activities of these films against a wide range of tested bacteria, whereas the antibiofouling activities of both composite films showed the best results against the Staphylococcus aureus and Escherichia coli biofilms. Biocompatibility studies showed that neither composite film exhibited any cytotoxicity or hemolysis. Conclusions: Obtained results indicate that these composite films could be used as antibacterial surfaces in the healthcare facilities.

Quantum Wire Coupled to Light

Experimental advances in cavity QED are raising the prospect of using light to probe quantum materials beyond the linear response regime. The capability to access quantum coherent phenomena would significantly advance the field. However, theoretical work on many-body systems coupled to light in the quantum coherent regime has been select. Here, we investigate the radiative properties of a finite-sized quantum wire in a microwave cavity. Examples of quantum wires include single-walled carbon nanotubes, a key experimental system in the field of nano-optics and plasmonics. We find that, for a variety of excited states, the repeated emission of photons results in the generation of many-body quantum entanglement. This leads to an increase in the rate at which subsequent photons are emitted, an example of Dicke superradiance. On the other hand, Pauli blocking tends to reduce this effect. Bosonization, the description of the excitations of a one-dimensional electron system as a gas of bosons, is found to be a powerful theoretical tool in this context. Its application means that many of our results generalize to wires with strong electron-electron interactions. The quantum wire thus represents a new platform to realize Dicke-model physics that does not rely on the various fine tunings necessary in traditional realizations involving many spatially isolated emitters. More broadly, this work demonstrates how quantum entanglement can be generated and measured in a many-body system. Published by the American Physical Society 2024

Role of Oxygen Defects in Eliciting a Divergent Fluorescence Response of Single-Walled Carbon Nanotubes to Dopamine and Serotonin.

Modulating the optical response of fluorescent nanoparticles through rational modification of their surface chemistry can yield distinct optical signatures upon the interaction with structurally related molecules. Herein, we present a method for tuning the fluorescence response of single-walled carbon nanotubes (SWCNTs) toward dopamine (DA) and serotonin, two structurally related monoamine-hydroxylated aromatic neurotransmitters, by introducing oxygen defects into (6,5) chirality-enriched SWCNTs suspended by sodium cholate (SC). This modification facilitated opposite optical responses toward these neurotransmitters, where DA distinctly increased the fluorescence of the defect-induced emission of SWCNTs (D-SWCNTs) 6-fold, while serotonin notably decreased it. In contrast, pristine, defect-free SWCNTs exhibited similar optical responses to both neurotransmitters. The underlying mechanisms for the divergent fluorescence response were found to be polydopamine (PDA) surface adsorption in the case of the fluorescence enhancement in response to DA, while the fluorescence decrease in response to serotonin was attributed to enhanced solvent relaxation effects in the presence of defects. Importantly, the divergent optical response of D-SWCNTs to DA and serotonin, via the introduction of defects, was validated in complex biological environments such as serum. Further, the generality of our approach was confirmed by the demonstrations of a divergent fluorescence response of D-SWCNTs suspended by an additional dispersant, namely lipid-polyethylene glycol (PEG). This study offers promising avenues for the broad applicability of surface functionalization of SWCNTs to achieve divergent responses toward structurally related molecules and advance applications in sensing, imaging, and diagnostic technologies.

Interactions and Click Functionalization of a Poly(Thiophenyl‐Tetrazine‐co‐Fluorene) Conjugated Polymer with Single‐Walled Carbon Nanotubes

A highly soluble thiophene‐based poly(tetrazine) polymer was prepared that can undergo inverse‐electron‐demand Diels‐Alder (IEDDA) click reactions efficiently with different types of trans‐cyclooctene (TCO) derivatives resulting in post‐polymerization functionalization. The resulting pyridazines post‐oxidation exhibited strong interactions with single‐walled carbon nanotubes (SWNTs) and showed selectivity toward metallic SWNTs. The resulting dispersions were used to prepare thin films, whose sheet resistivity was measured. It was found that TEG functionalized pyridazine dispersion film resulted in a lower sheet resistance by several orders of magnitude compared to the non‐clicked tetrazine dispersion indicating better conductivity post‐IEDDA. Furthermore, modification of the polymer backbone while bound to the SWNT was performed successfully, preserving the properties of the nanotubes.

Symmetry and Asymmetry in Mutations and Memory Retention during the Evolutionary Growth of Carbon Nanotubes.

Symmetry is a motif featured in almost all areas of science, and understanding the mechanism of symmetry breaking is challenging. Similar to mutations that disrupt symmetry in evolution, defects in materials offer insight into symmetry breaking. Here, we investigate symmetry in intragenerational mutations and symmetry breaking in transgenerational mutations in the evolutionary growth system of carbon nanotubes (CNTs). Mutations caused by pentagon-heptagon (5-7) pairs in different conformations shorten the lifespans of single-walled carbon nanotubes (SWNTs) by acting as time markers during growth. Symmetric distributions are observed for intragenerational mutations from (n, m) to (n + i, m-i) (where i ∈ caslon Z) with different appearance orders of pentagon and heptagon. Such symmetry breaks occur in transgenerational mutations. Intragenerational mutations occur multiple times on a SWNT, oscillating regularly between i and - i until termination occurs. These types and effects are retained in the form of memory to encode SWNTs during subsequent growth, resulting in a length reduction after each mutation. Our results provide a profound understanding of symmetry breaking and memory retention and offer guidance for the controlled synthesis of materials.

A Promising Approach to Ultra-Flexible 1 Ah Lithium-Sulfur Batteries Using Oxygen-Functionalized Single-Walled Carbon Nanotubes.

Lithium-sulfur (Li-S) batteries represent a promising solution for achieving high energy densities exceeding 500Wh kg-1, leveraging cathode materials with theoretical energy densities up to 2600Wh kg-1. These batteries are also cost-effective, abundant, and environment-friendly. In this study, an innovative approach is proposed utilizing highly oxidized single-walled carbon nanotubes (Ox-SWCNTs) as a conductive fibrous scaffold and functional interlayer in sulfur cathodes and separators, respectively, to demonstrate large-area and ultra-flexible Li-S batteries with enhanced energy density. The free-standing sulfur cathodes in the Li-S cells exhibit high energy density maintaining 806 mAh g-1 even after 100 charge-discharge cycles. Additionally, oxygen-containing functional groups on the SWCNTs significantly improve electrochemical performance by promoting the adsorption of lithium polysulfides. Employing Ox-SWCNTs in both cathodes and interlayers, the study achieves high-capacity Li-S pouch cells that consistently deliver a capacity of 1.06 Ah and a high energy density of 909 mAh g-1 over 50 charge-discharge cycles. This strategy not only significantly enhances the electrochemical performance of Li-S batteries but also maintains excellent mechanical flexibility under severe deformation, positioning this Ox-SWCNT-based architecture as a viable, light-weight, and ultra-flexible energy storage solution suitable for commercializing rechargeable Li-S batteries.

Scalable Photonic Nose Development through Corona Phase Molecular Recognition.

Breath sensors promise early disease diagnosis through noninvasive, rapid analysis, but have struggled to reach clinical use due to challenges in scalability and multivariate data extraction. The current breath sensor design necessitates various channel materials and surface functionalization methods, which delays the process. Additionally, the limited options for channel materials that provide optimum sensitivity and selectivity further restrict the array size to a maximum of only 10 to 20 channels. To address these limitations, we propose a breath sensing array design process based on Corona Phase Molecular Recognition (CoPhMoRe), which enables the creation of an expansive library of nanoparticle interfaces and broad fingerprints for multiple analytes in the breath. Although CoPhMoRe has predominantly been utilized for liquid-phase sensing, its recent application to gas-phase sensing has shown significant potential for breath sensing. We introduce the recent demonstrations in the field and present the concept of a CoPhMoRe-based photonic-nose sensor array, leveraging fluorescent nanomaterials such as near-infrared single-walled carbon nanotubes. Additionally, we identified four critical milestones for translating CoPhMoRe into breath sensors for practical clinical applications.

Polyethylene glycol-phospholipid functionalized single-walled carbon nanotubes for enhanced siRNA systemic delivery

Small interfering RNAs (siRNA) technology has emerged as a promising therapeutic tool for human health conditions like cancer due to its ability to regulate gene silencing. Despite FDA-approved, their delivery remains localized and limiting their systemic use. This study used single-walled carbon nanotubes (SWNTs) functionalized with polyethylene glycolated (PEGylated) phospholipids (PL-PEG) derivatives for systemic siRNA delivery. We developed an siRNA systemic delivery vehicle (SWNT-siRNA) by conjugating SWNT functionalized with PL-PEG containing either amine (PA) or maleimide (MA). The functionalized SWNT with a lower molecular weight of PA produced the SWNT-siRNA conjugate system with the highest stability and high siRNA loading quantity. The system delivered siRNA to a panel of tumour cell lines of different organs (i.e. HeLa, H1299 and MCF-7) and a non-cancerous human embryonic kidney 293 cells (HEK293T) with high biocompatibility and low toxicity. The cellular uptake of SWNT-siRNA conjugates by epithelial cells was found to be energy dependent. Importantly, the presence of P-glycoprotein, a marker for drug resistance, did not inhibit SWNT-mediated siRNA delivery. Mouse xenograft model further confirmed the potential of SWNT-siRNA conjugates with a significant gene knock-down without signs of acute toxicity. These findings pave the way for potential gene therapy applications using SWNTs as delivery vehicles.

Enhanced Thermoelectric Generator Power Output Based on Electrodeposited Bi2Te3 Nanocomposites with Pt NPs-CNTs Through Multiphysics Simulation

Thermoelectric generators (TEG) possess the potential to transform unused heat into electrical energy, making thermoelectricity a viable alternative for addressing the energy issue. This study provides insight into the enhanced power density of a TEG device when embedded with bismuth telluride (Bi2Te3) nanocomposite. The TEG power density has been analysed under the fluid flow simulation condition by utilizing several Bi2Te3 nanocomposite materials with Pt NPs-CNTs inclusion. The impact of static and steady air flow conditions has been studied using a detailed computational fluid dynamics (CFD) parameter, with flow velocities of 0.01 m/s and 1 m/s. As a main part of the work, the power density of nanocomposites embedded as N-type legs was compared to that of pure material. The Bi2Te3 with hybrid nanocomposite produces the highest power density, precisely combining Bi2Te3 with platinum nanoparticles (Pt Nps) and single-wall carbon nanotube (SWCNT) materials (Bi2Te3/Pt-SWCNTs). At velocity of 1 m/s, the power density was calculated to be 156.85μW/cm2, which increased to 158.86 μW/cm2 at a fluid velocity of 1 m/s, marking an 88% increment compared to the TEG model using pristine Bi2Te3 and higher than that of the previous work about 4 times of increment.

Alkali metal ion storage of 2,6-naphthoquinone molecules encapsulated in single-walled carbon nanotubes

Due to its lower cost, environmental friendliness, and higher energy density, 2,6-naphthoquinone (NQ) demonstrates potential as an electrode material in lithium/sodium ion batteries. However, the limitations of poor conductivity and easy dissolution in electrolyte hinder its practical application. In this study, we employed single-walled carbon nanotubes (SWCNTs) as a protective capsule for encapsulating NQ molecules to address these challenges. The characteristics of NQ molecules encapsulated within SWCNTs (NQ@SWCNTs) were investigated using thermogravimetric analysis, x-ray photoelectron spectroscopy, x-ray powder diffractometry, and Raman measurements. Charge–discharge experiments of lithium/sodium ion batteries were conducted on both pristine NQ molecules and NQ@SWCNTs. Furthermore, we discussed the observed disparities in charge–discharge curve between NQ@SWCNTs and bare NQ.

Investigation of surface modified armchair type (5,5) single walled carbon nanotube with Si and B dopant atoms towards the evaluation of selective delivery of aceclidine drug: A DFT approach

Investigation of surface modified armchair type (5,5) single walled carbon nanotube with Si and B dopant atoms towards the evaluation of selective delivery of aceclidine drug: A DFT approach

Triple-helix β-glucan-based self-assemblies, synthesis, characterization and anticarcinogenic effect.

Triple negative breast cancer (TNBC) seriously endangers women's life and health due to its high invasion and mortality. Reactive oxygen species (ROS) mediated tumor cells apoptosis is considered an effective anticancer approach. Herein, we designed a natural active triple helix β-Glucan (BFP) wrapped single walled carbon nanotubes (SWNTs)-loaded doxorubicin (DOX) self-assembly (BSD) via generating excess ROS to induce oxidative stress damage for TNBC therapy. BSD could directly consume glutathione (GSH) to promote ROS. In vitro results demonstrated that BSD exhibited obvious antitumor effects to breast cancer cells by promoting apoptosis. Un-targeted metabolomics under molecular level identified the specific metabolic targets and unveiled that BSD markedly disturbed multiple metabolic pathways, including purine metabolism, pentose phosphate pathway, glutathione metabolism pathways, amino sugar and nucleotide sugar metabolism and energy metabolism, led to the inhibition of DNA and RNA synthesis, the generation of ROS, the exacerbation of DNA damage, the disruption of cell membrane integrity and the decrease of ATP. In vitro and in vivo oxidative stress assays further verified that BSD significantly promoted intracellular oxidative stress and resulted in cell damage. This study provides theoretical basis for the development and screening of new drugs based on ROS therapy for TNBC.

Numerical method for modeling of a polymer matrix modified with single-wall carbon nanotubes

Numerical method for modeling of a polymer matrix modified with single-wall carbon nanotubes

Simulation and non-similar analysis of magnetized SWCNT-MWCNT hybrid nanofluid flow in porous media using Darcy-Forchheimer-Brinkman model

The field of hybrid nanofluid transport through porous media holds immense promise for optimizing thermal processing and various thermodynamic applications. This study investigates the flow dynamics of a hybrid nanofluid, comprising water and a synergistic combination of single-walled and multi-walled carbon nanotubes (SWCNT-MWCNT), as it traverses a vertically stretched porous surface. The mathematical modeling of this flow scenario considers the influential factors of magnetohydrodynamics (MHD), viscous dissipation, heat sources, and ohmic heating. The Darcy-Forchheimer-Brinkman model is employed to capture the transport of fluid through the porous medium. Through the application of Local Non-Similarity (LNS) technique, the governing equations are converted into a dimensionless system and solved numerically using the robust bvp4c function in MATLAB. Interestingly, higher values of heat source parameter leads to a rising trend in the temperature profile, highlighting the intricate interplay between the thermal and fluid dynamic aspects of the system. This work provides valuable insights into the tailored design of hybrid nanofluids and porous media configurations to harness their enhanced thermal transport capabilities, with potential applications in diverse fields such as energy storage systems, heat exchangers, and thermal management devices. The findings contribute to the broader understanding of hybrid nanofluid transport in porous media and pave the way for the development of innovative thermal management solutions in a wide range of industrial and technological domains.

Design of a tunable microlens based on hybrid single-wall carbon nanotube and liquid crystal

: Tunable liquid crystal (LC) lenses have garnered significant interest in recent years for their lightweight, cost-effectiveness, and versatility in applications like augmented reality, ophthalmic devices, and astronomy. Despite numerous proposed structures to enhance LC lens performance, achieving a minimal focal length while preserving image quality and balancing cost and complexity remains a daunting challenge. Adaptive microlenses encounter these obstacles due to physical constraints and diffraction effects. One promising solution lies in using adaptive LC-carbon nanotubes (CNTs) lenses. By adjusting external stimuli like electric or magnetic fields, it is possible to modify the refractive index distribution of the LC medium, thus changing the focal length of the microlens. When paired with CNTs, the LC molecules' orientation and control of focal length can be even more precise. Our research findings suggest that to achieve the shortest focal length in a microlens with a thickness of 22.5 μm, it is recommended that the diameter of the CNT should not exceed 10 nm, and the height of CNT should fall within the range of 10 to 20 μm considering the presence of screening effect. Conversely, for a microlens with low full width at half maximum (FWHM), narrower light spot, it is advisable to use CNT with a diameter larger than 100 nm and a height greater than 13 μm. Additionally, for a microlens with an efficient Fresnel number in the range of 1 to 10, the microlens should have CNT with widths from 100 to 200 nm. Therefore, based on the importance of each factor (focal length, FWHM, and Fresnel number), the dimensions of the carbon nanotube can be selected to suit the desired application.